This invention relates generally to medical parameter monitoring and more particularly to an integrated medical monitoring system for use in a clinical setting. The medical monitoring system includes local patient monitors, remote central stations, and remote access devices, all of which are preferably networked together through a wireless communication system to provide overall patient care as well as data storage and retrieval through a single system. The communications between various components of the system are bi-directional, thereby affording the opportunity to establish monitoring parameters from remote locations, provide interactive alarms and monitoring capabilities, and provide data exchange between components of the system.
Although systems for remote medical monitoring of patient physiological parameters are presently available, these systems suffer from some notable disadvantages. Some systems depend on a hardwired system which requires that patients be disconnected from a monitor, connected to a mobile monitor in transit, and then reconnected to the system at a new location. Furthermore, an additional monitor and often different sensor devices must be attached to the patient when the patient is in transit. These systems, therefore, are inefficient for use in clinical settings where patients are frequently transferred between various facilities.
Other systems employ wireless communications, but these are generally unidirectional RF transmissions from the monitor to the remote display only. Typically, physiological signal data is transmitted in analog form. The analog signal quality received at the remote display/control unit tends to be dependent upon the distance from the transmitter to the antenna(e); objects (building components, movable objects, etc.) in between the transmitter and receiver may compromise performance. Furthermore, transmission technologies such as UHF, which employ a particular base frequency for data transmission, face serious problems due to interference from other transmission sources which happen to be transmitting at or near the same frequency. These systems, therefore, suffer from low quality signals. Furthermore, due to the unidirectional nature of the communications, the care giver at the remote location cannot select which data is necessary to properly monitor a given patient, or select value ranges for various types of monitoring. Remote patient monitoring, therefore, is limited to performing pre-programmed tasks.
In still other cases, physiological data is initially filtered to determine when a limit has been reached, and an alarm is transmitted to a viewing station only when a predetermined alarm limit has been met. While generally providing a paging function, these devices do not provide for remote monitoring in a clinical setting or the transfer of large amounts of data.
Due to the limited communications between monitors and remote viewing locations, data transfer between systems is also problematic in prior art systems. Data collected in one remote display/control device must be loaded to a floppy disk or other transportable memory device and transported to another system. Therefore, it is difficult to maintain an electronic database of patient information for recordation, archiving, or analysis purposes.
Furthermore, when an emergency situation occurs, prior art systems generally require a relatively long time period to determine that an emergency has occurred and to broadcast the signal to a remote caregiver. This delay is extremely important in critical care monitoring, where a matter of seconds can make a significant difference in the outcome of a patient experiencing a life-threatening condition. For example, most available medical alert systems do not include an integrated paging system for providing appropriate information to a remote caregiver. Instead, an external paging system is often connected. These external paging systems must access a clinical database, search the data collected in databases for emergency situations, and determine when to provide a paging signal. These steps require that communication links be established between disparate equipment, and that a significant amount of data be processed before an emergency is detected, thereby wasting critical time. Furthermore, once an emergency situation is found, prior art systems generally provide a paging signal through a standard paging system. Publicly available paging and other communication systems, however cannot be controlled by the user. Frequently, these systems are overloaded at peak use times, thereby adding a further delay to the delivery of a medical alert system
Other problems associated with prior art medical alert systems include difficulties associated with controlling the broadcast of a message and difficulties associated with determining whether an emergency message has been received. The public communications systems relied on many medical systems are prone to failure or to closure due to business decisions or bankruptcies. A medical alert system relying on such a communications system can, therefore, suddenly discover that it has lost medical alert capabilities. Furthermore, prior art systems often do not provide the communications systems necessary to alert the sending system that a message has been received, read, or responded to by a caregiver, or to determine whether a receiver is activated and capable of receiving a message.
Other prior art systems which incorporate wireless communications often depend on FM or other types of communication links which are prone to interference, have limited bandwidth capabilities, and generally provide insufficient data to a caregiver receiving a page. Furthermore, these devices often do not include a reply or response system which can guarantee that a message has been received, or that the receiving device is operational.
Prior art monitoring systems often also require the manual transfer of information to patient medical records, including waveform data which is often printed from a monitoring device, and is then cut and pasted into the patient""s medical records. Manual record keeping of this type, including the manual entry of prescription data, physiological data, and even insurance and billing data, is prone to error.
There remains a need, therefore, for an integrated medical monitoring system which provides bi-directional, wide bandwidth communications between a number of elements including patient monitors, central monitoring systems, medical alert systems, and analysis systems to allow both monitoring and sharing of collected data for data intensive physiological parameters and waveforms. Such a system preferably would include an electronic data entry system such as a bar code scanner or other device to simplify entry of data, and to simplify transfer of data to an overall clinical information system. Preferably the clinical information system would include data such as billing and insurance information, laboratory results, and vital sign and waveform information in electronic medical records.
It is therefore an object of the invention to provide an integrated medical monitoring system which includes local patient monitors, central viewing stations, and remote access devices, and an electronic data entry system.
It is another object of the invention to provide an integrated medical monitoring system including patient monitors, central monitoring systems, and remote access devices using bi-directional data transmission.
It is a further object of the invention to provide a novel medical monitoring system that enables dynamic control of remote monitoring simultaneously with medical parameter and/or waveform data acquisition.
It is yet another object of the invention to provide an improved medical monitoring system which can receive and control a plurality of medical parameters and/or waveforms being monitored at remote locations.
It is a further object of the invention to provide a component which can be used therewith to automatically acquire and store data pertaining to various physiological parameters.
It is yet another object of the invention to provide a telemetry system which enables automatic acceptance of patient data and immediate analysis thereof and/or comparison with previously-acquired data.
It is another object of the present invention to use RF communication and automatic registration of critical data, as well as in combination with frequency hopping, spread spectrum technology, to provide significantly improved results which are surprising and unexpected in view of the prior art.
It is further object of the invention to provide a medical monitoring system which enables transmission of messages, including medical alert, from the central monitoring system to wireless, remote access devices, which may themselves reply or communicate with each other.
It is yet another object of the invention to provide a medical monitoring system in which medical alert messages can be automatically formatted to include time of alert, patient identification, patient location, alert condition and priority, vital signs data, and physiological waveform data.
It is a further object of the invention to provide a medical monitoring system in which secure delivery of a medical alert message can be guaranteed by utilizing an integral wireless communications system, and through monitoring for responses from the remote access device to the medical alert.
It is yet another object of the invention to provide a medical monitoring system which enables maintenance of the remote access device""s message memory in such a way as to guarantee that space is available for new medical alerts.
It is yet another object of the invention to provide a medical monitoring system which enables automatic transfer of patient data from the central monitoring system to auxiliary systems for analysis, display, storage and/or retrieval.
The present invention comprises an integrated medical monitoring system preferably including at least one local patient monitor, at least one central monitoring system, and at least one remote access device. These components are linked in a network which preferably comprises a wireless RF system. Most preferably, the communications links comprise frequency-hopping, spread spectrum RF communications in the ISM frequency band. However, other wireless communication systems, including IR, may also be used.
The local patient monitor provides sensors for monitoring a number of physiological parameters including but not limited to ECG (electrocardiogram), NIBP (non-invasive blood pressure), SpO2 via pulse oximetry, respiration, temperature, invasive pressure lines, gas monitoring, and cardiac output. The local patient monitor preferably includes a transceiver, or a transmitter and a receiver, a display and keyboard. The patient monitors can operate independently as a monitoring device, as well as transmit data to and receive monitoring control signals from a central monitoring system. To facilitate entry of data such as patient identity, caregiver identity, pharmaceuticals received, and various other data, the patient monitor preferably includes an electronic data entry device such as a bar code scanner, which can provide coded patient information to transmit to the central monitoring system or a clinical information system, as will be described below.
The central monitoring system comprises a display, a transceiver or a transmitter and a receiver, and memory storage for storing patient data. The central monitoring system receives data from the local patient monitors, displays this information to caregivers at the central monitor, and stores the data for archival and analysis purposes. Preferably, archival records associated with a given patient can be transferred to another central monitoring system or an auxiliary system either through wireless communications or through a hardwired network link between two or more central monitoring systems. A caregiver at the central monitoring system can select among the subset of available waveforms and vital sign data most appropriate for remote display, and this selection is transmitted to the patient monitor. The central monitoring system preferably also includes a scanner for facilitating data entry and retrieval of stored waveforms. The central monitoring system can store timed events, including timed activity charts which show a patient""s physiological response versus various activity and exercise levels.
The central monitoring system also monitors incoming data from the patient monitor for medical alert messages, and continually monitors incoming data for possible emergency situations. When an emergency is found, the central monitoring system directly alerts the remote access device through the wireless transceiver. This integrated system eliminates processing and communication steps common in prior art devices. Preferably, the communication link is via a spread-spectrum RF system in the ISM band, thereby providing a high bandwidth transmission with limited extraneous interference, permitting the transfer of continuous waveforms and detailed vital sign information to a remote access device with limited interference.
The remote access device can comprise any of a number of electronic devices including paging systems; personal digital assistants (PDAs); telephones; or laptop, desktop, or other types of computers. Preferably, these devices are fitted with a transceivers to receive data from and transmit data to the wireless communications network described above. Due to the bandwidth of these communications, a significantly higher amount of data can be transmitted than in a standard paging system. Furthermore, because this system does not depend on communications through a standard pager system, problems associated with paging and cellular phone systems, such as busy or temporarily disabled or closed systems which might delay or prevent the receipt of a message, are averted. This is particularly important in applications in which an emergency or alarm signal is sent. Additionally, due to the bi-directional capabilities of the communications link, the sending system can determine that a caregiver has read and responded to a message. The sending system can also verify the availability of memory in a remote access device, and delete unnecessary messages to provide additional space. Therefore, the present invention provides a preferred system for medical alert system critical care monitoring, in that it is able to transmit the message in a timely fashion and verify that it has been delivered and read by an appropriate caregiver.
As noted above, the remote access devices preferably communicate bi-directionally. Due to these bi-directional communication capabilities, a caregiver can obtain updated information from the central monitoring system by requesting data from the remote access device. To facilitate such requests, remote access devices preferably include an electronic data entry device such as a bar code reader so that a caregiver in a remote location may easily scan a bar code to identify a given patient to obtain data. As noted above, the wide bandwidth of the wireless, preferably RF, system allows for a significant amount of data to be transmitted including vital sign statistics and waveforms of various physiological parameters. Because the devices can also communicate with each other, a first caregiver receiving such data in an alarm or other condition can also choose to forward the information to a second caregiver, or forward free-form text to the central monitoring system or the patient monitor itself. Such message may include care instructions or instructions to contact a specialist, thereby allowing a primary physician the opportunity to direct care remotely. Furthermore, although the remote device has been described as part of an overall system, it will be understood that such a device could be operated independently with one or more patient monitors including bi-directional communication capabilities as described above.
The remote access device can alternatively be operated as a medical alert system in which either the patient monitor directly contacts the remote device on discovering an alarm condition or the patient monitor transmits this information to the central monitoring system. The central monitoring system, in turn, transmits the information to the remote access device. The remote access device can include a GPS or other locating system which allows the sending system, whether the patient monitor or the central monitoring system, to determine the location of a plurality of caregivers and select an appropriate primary recipient of the alarm message based on location. The alarm system preferably determines an initial primary recipient based on location, specialty, and/or relationship to the patient (i.e. the patient""s primary physician), and then waits for a signal from the remote device indicating that the message has been received and read. Preferably, this signal is sent automatically, although in some cases the recipient may send a coded response such as a password to the system. If a response is not received within a preselected time period, or if the response is negative, the message is sent to one or more secondary recipients. Preferably, the primary device receives a list of secondary recipients and the preselected time frame to forward the message and the primary device notifies the secondary device without further interaction with the sending system. Alternatively, however, this function can be handled by the sending system.
The central monitoring system further comprises a maintenance function which employs the bi-directional communication link between the central monitoring system to verify the available memory space and working status of the remote access devices. The central system can evaluate the data in the remote access device memory and delete unnecessary messages to assure that the device is operational for future data deliveries. Furthermore, upon delivery of data to a remote access device, the central monitoring system can detect when data has been secured and when data has been read. This function is particularly useful in time-sensitive medical emergency situations.
Preferably, the medical monitoring system also comprises at least one auxiliary system for transmitting and receiving clinical data, thereby providing a more complete overall medical monitoring and recordation system. The auxiliary system can be connected to the medical monitoring system via a hardwired network link, or through a wireless communication link. The auxiliary equipment can comprise a diagnostic workstation such as an ECG diagnostic workstation, a clinical information system, or other database system. Diagnostic workstations receive selected archived physiological data such as vital sign data, waveforms, timed cardiac events, or other events from the central monitoring system or a patient monitor for further clinical analysis by a caregiver. Clinical information systems store patient medical records such as demographics, assessments, diagnoses, care plans, notes, physiological waveform data, vital signs, laboratory, and other results, prescription and pharmacy information, insurance and billing information, and other personal patient information. Preferably, the information in the clinical information system is coordinated based on an identification number assigned to a patient when entering the hospital. This number, represented as a bar code, can the be used by the patient monitor and the central monitoring system to simplify the storage, retrieval, and transfer of patient data. Preferably, therefore, all devices through which data is entered, archived or retrieved include a bar code scanner or other electronic entry device.
Other objects, features and advantages of the present invention will be apparent from the following description of the preferred embodiments, taken in conjunction with the accompanying drawings described below wherein like components have like numerals throughout several views.